Rock drill



1,. w. GREVE 1,894,398

Rocx DRILL Filed May 24, 1928 l. l. lf.

Jan. 17, 1933,

Mim/mw Patented Jan. 17, 1933 UNITED STATES luirl-:la'r oI-fmcle:r

Louis W. ver'arzvnorv CLEVELAND, omanssIeNon 'ro THE craivnnannl Qnocx DRILL .coi/rPANY,` or QLEVELAND, oHro ROCK Application filedV May 24,

The present invention is directed p-rovements in rock drills.

The primary object of the invention is to provide novel means for advancing thedrill to its work, the construction beingv adaptable to that type of drills known as Stopers.l Y

Another object of the, invention is to pro-V Vide simple and efficient means for cutting to imoff the pressure fluid to the feed cylinder ments, and arrangement of parts, hereinafter to be fully described and pointed out in the appended claims.

In the accompanying drawing, in which similar characters of reference denote like and corresponding parts throughout several views:

Figure 1 is a longitudinal sectional view. Figure 2 is a similar view of a modified for Figure 8 is a fragmentary side view.

Referring to the drawing, 1 designates the cylinder in which is operable the piston hammer 2, reciprocatory movement being im parted to said hammer by pressure fluid flowing from the pocket 3 in the head block fi, such fluid entering the pocket through the port 5. A valve seat 6 is formed in the head block and rotatable therein is a throttle valve 7 of conventional form, which is operable to control the flow of pressure fluid to the pocket. The head blockhas a passage 8 formed longitudinally therein which leads from the valve seat 6 and communicates with the lateral passage 9 formed with a tapered seat 10. The seat l0 opens into a chamber 11 in which is movable the stem of the needle valve 12, said valve including a shank 13 threaded for adjustment in the opening 14 formed in said head'block. The outer end of the shank DRILL y 1928. Serial No. 280,189.

has a wheel lfixed thereto and provided l with peripheral notches 16 for engagement with the spring finger 17 fixed to the outer side of the head block. Obviously the finger i7 when engaged in a-notch of the wheel will hold the needle valve in adjusted position. Leading from the chamber 11 is a duct 18,

the purpose o-f which will be later explained.

A flanged bushing 19 isemployed and vis fitted in the upper end ofthe feed cylinder 20, said bushing having an annular groove 2l formed in its Lipper surface which communicates with the feed cylinder through ducts 22. Arotating valve 23 is fitted in the socket 24 of the head block and has a por-t 25 which can be placed in registration with the passageway 26 leadingfrom` the groove 2.1 in order that fluid may be exhausted through the valve to atmosphere.

Movable in the feedl cylinderl 20 is the packed head 27 of the feed piston 28, said piston being hollow and is adapted to extend through the plug 29 fixed in the lower end of' the feed cylinder, as customary. .To .exhaust any pressure fluid which Imight leak by the head 27 the cylinder has a perforation 30 formed therein. y

Briefly the operation is as follows: f Assuming that. the needle valve is unseated and pressure fluid from the line enters the passages 8V and 9, around the needle valve,

through the duct 18 to the annular groove 21 and from thence through the ducts 22 to ac t upon the head 27, which causes the feed piston to move outwardlywithout resistance owing to the presence of the perforation 3.0. It is desirable at times to vvary the pressure upon the feed piston laccording to the material being drilled, such for instance hard or soft rock. This is readily accomplished upon adjusting the needle valve away from its seat tofincrease the pressure by permitting a greater flow of pressurefluid from. the duct 8 to the duct 18 and toward its seat for de' creasing pressure by restricting the flow of pressure fluid from the duct 8 to the d uct'18. The valve 23, when the device is in opera' tion, is closed to permit fluid pressure to build up in the chamber behind the feed piston 27. When this valve is opened the feed cylinder is exhausted to atmosphere and the piston may then be retracted. rIhe needle valve can obviously be held in adjusted positions by the spring finger 17.

In the modified form of the invention the passage 8 does not have associated therewith the needle valve to control the flow of pressure fluid from the throttle valve to the annular groove 21 toV act upon the head 27. The 'head bloclr in this instance has 'a passage 31 leading from the annular groove 21 to the chamber 32 in which operates the neef dle valve 33 for controlling the passage of fluid fromthe passage 31 to the passage 34.

which leads to the rotating valve 35. The construction. of the needle valve is identical to that ofthe preferred form of the invention.

1 Obviouslywhen pressure fluid enters the i chamber 36 in the bushing 19 it will act upon the feed piston to move the same outwardly from the feed cylinder. The quantity of pressure fluid released from the feed cylinder can be conveniently regulated upon adjusting f the needle valve 33 to control the flow Vof fluid through the passages 31 and 34. The adjustment of the needle valve 33 in this form of the invention, in effect, restricts the egress of fluid from the feed cylinder. rIhe wider this valve is opened the less will be the pressure inthe cylinder and vice versa.- It will be observed that the modified form of the invention has parts identical to those of the preferred form, differing therefrom by placing the needle valve so as to control the egress of fluid from theA feed cylinder instead of the ingress thereto. v f

lVVhatis claimed is v Y f 1. In a pneumatic toola cylinder having al hammer piston reciprocable therein, a feed cylinder having a feed piston reciprocable therein, a head block ydisposed between said cylinders, a bushing fitted in said feed cylinder, there being an annular groove in said bushing, there being a passage communicating said groove with'the interior of said feed cylinder, there being a fluid pressure inlet and a fluid pressure outlet, in said head block, there being a passage-way in said head block communicating said inlet with said groove and a second passage-way in said head block communicating said outlet with said groove, and means for restricting the liow of pressure fluid through one of said passages.

2. In a pneumatic tool a cylinder having a hammer piston reciprocable therein, a feed cylinder having a feed piston reciprooable therein, a head bloclrdisposed between said cylinders, a bushing fitted in said feed cylinder, there being an-annular groove in said bushing, there being a passage communicating said groove with the interior of said feed cylinder, there being a fluid pressure inlet and a fluid pressure outlet, in said head block, there being a passage-way in said head block ya hammer piston reciprocable therein, a feed cylinder having a feed piston reeiprocable therein, a head block disposedv between saidv cylinders, a bushing fitted in said feed cylinder, there being an annular groove in said bushing, there being a passage communicating sai-d groovewth the interior of said feed cylinder, there being a" fluid pressure inlet and a fluid pressure outlet, in said' head block, there being a passage-way in said head block communicating said inlet with said groove and asecond` passage-wayin said head block communicating said outlet with said groove, and means for restricting the floW of pressure fluid throughv the'passage which communicates said outlet with said groove. i

In testimony whereof I affix my signature.

Louis w. cnnvn fle 

